Moisture-removal equipment for pneumatic systems are known in the prior art. One such prior art moisture-removal apparatus is described in Japanese Utility Model No. 54-24773 (Jikkai). This moisture-removal apparatus is illustrated in FIG. 6. In FIG. 6, the main body of the moisture-removal apparatus is designated 10. Connected for fluid communication with an inlet 12 on the main body 10 is an air compressor 20. An air reservoir 30 is connected for fluid communication with an outlet 13 on the main body 10. A drain valve 40 is connected to a drain outlet 14, positioned adjacent the bottom portion of the main body 10. Furthermore, there is a check valve 15, in which the direction of outlet 13 is the normal direction, and a throttle 16, which is parallel to check valve 15, provided on the main body 10 of the prior art moisture-removal apparatus. An absorbent body 1 is positioned in a containing chamber 11 that is formed in the main body 10. The absorbent body 1 includes a number of fluid penetration apertures 2 in the axial direction (vertical direction in FIG. 6), and an absorbent 3 is contained between the adjoining penetration aperture 2 to form a honeycomb-shaped cylinder. In addition, there is a filter 19 provided at the inlet side end surface of the absorbent body 1.
In operation of this prior art moisture-removal apparatus, when the air compressor 20 is operating, the compressed air discharged from such air compressor 20 is communicated into the main body 10 from the inlet 12 and reaches the filter 19 adjacent the one end surface (lower surface in FIG. 6) of the absorbent body 1. The air is communicated in the axial direction of the absorbent body 1 and is dried by the absorbent 3 while it passes through the penetration apertures 2.
The air thus dried exists through the other end surface (upper surface in FIG. 6) of the absorbent body 1 and, after passing through the check valve 15, is communicated to the air reservoir 30 from the outlet 13 in the main body 10 of the moisture-removal apparatus. During the time the air compressoir 20 is in operation, the drain valve 40 is closed. When the air compressor 20 is shut off, the drain valve 40 opens and at least a portion of the dried air stored in the air reservoir reverse-flows inside the absorbent body 1 through the outlet 13 and the throttle 16. After the absorbent 3 is regenerated by this reverse-flow of dried air from the air reservoir, the air is discharged from the main body 10 via the drain valve 40.
One problem with this type of prior art moisture-removal equipment is that the compressed air from the air compressor 20 is supplied via narrow tubing. Consequently, when the compressed air flows into the main body 10, it will tend to cause channeling. Such channeling depends upon the flow direction and/or the flow amount. In addition, the air passage resistance in the penetration apertures 2 of the absorbent body 1 is generally smaller than that in the case which the granular absorbent particles are filled. Further, because these penetration apertures 2 are independent from each other, the above-mentioned channeling effect will not be corrected in the absorbent body 1. For this reason, the entire absorbent 3 may not be used evenly and, as a result, the specified drying capacity of the moisture-removal apparatus will not always be obtained.